Table 2. Skeletal muscle fiber cross-sectional area, fiber type, and capillary and nuclear density in the longissimus muscle of beef cattle from different stocker management programs at the conclusion of the stocker and finishing phases
Variable | Stocker management program | SEM | p-value |
CON | CORN | LGWP | HGWP |
Intermediate harvest | | | | | | |
Fiber area (μm2) | 1,902.06c | 1,850.04c | 2,458.69a | 2,159.87b | 38.09 | < 0.0001 |
Type 1 muscle fibers (%) | 31.62x | 28.01xy | 26.79y | 28.00xy | 1.35 | 0.0572 |
Type 2 muscle fibers (%) | 68.38x | 71.99xy | 73.21y | 72.00xy | 1.35 | 0.0572 |
Capillaries/mm2 | 66.60x | 49.40y | 48.15y | 58.55y | 5.62 | 0.0781 |
Nuclei/mm2 | 674.00 | 629.65 | 660.50 | 658.40 | 19.19 | 0.4234 |
Final harvest | | | | | | |
Fiber area (μm2) | 3,015.05b | 3,209.15a | 2,927.39b | 2,471.57c | 56.04 | < 0.0001 |
Type 1 muscle fibers (%) | 27.82xy | 26.77y | 31.13x | 29.40xy | 1.23 | 0.0720 |
Type 2 muscle fibers (%) | 72.18xy | 73.23y | 68.87x | 70.60xy | 1.23 | 0.0720 |
Capillaries/mm2 | 67.30a | 45.95b | 41.30b | 50.05b | 5.10 | 0.0034 |
Nuclei/mm2 | 598.15a | 585.25ab | 542.95b | 572.90ab | 18.41 | 0.1862 |
Least square means within a row lacking a common superscript differ (p ≤ 0.05).
Least square means within a row lacking a common superscript tend to differ (0.0501 ≤ p ≤ 0.10).
SEM, standard error of the LS mean.
CON, 40% crude protein cottonseed meal-based supplement on dormant native range; CORN, corn and soybean meal-based supplement on dormant native range; LGWP, re-duced rate of gain on wheat pasture; HGWP: high rate of gain on wheat pasture.